The American Type Culture Collection (ATCC) located in Rockville, Maryland, is a national repository dedicated to the collection, preservation, and distribution of authentic cultures of animal and plant viruses, bacteria, bacteriophages, cell lines, fungi, hybridomas, plant tissues., recombinant DNA vectors, and oncogenes. The ATCC distributes over 150,000 of these cultures and cell lines each year. These biological materials are important to the full spectrum of NIH-supported biomedical research from basic to clinical investigations. The ATCC also offers a number of services to the scientific community such as culture identification and mycoplasma contamination testing, in addition to offering workshops for new techniques in culturing and molecular biology. The ATCC is also the primary source of microbiological standards for the scientific community. The Program administers a contract which supports the curatorial functions of this unique resource.